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Reading Werner Heisenberg’s “Physics and Philosophy” (1958), and talking about it with an actual former particle physicist, Dylan Casey.
What weird stuff about reality does quantum physics imply? Is Heisenberg (of the Uncertainty Principle fame) right that we need to reject “metaphysical realism” based on this very well established scientific framework? The discussion ranges over the uncertainty principle, relativity, wave/particle duality, Pre-Socratic metaphysics, why Kant is wrong about space, and lots of very weird things.
Read the text online or purchase it.
Plus, we spend far too much time talking about an article by Thomas Nagel about intelligent design; you can read that here. And the blog post by Brian Leiter that got us talking about it is here.
End song: “Neutrino of Love,” written and sung by Dylan Casey, with backing and production by Mark back in 1997 or so (remixed and cleaned up just now). A different version appears on his Neutrino Sessions album.
Five Stars after 100+ iTunes Ratings.
#1 by Dan B on January 18, 2010 - 5:45 am
I enjoyed the episode. Quantum mechanics is very bizarre and I get the feeling after studying it that although we have learned many interesting things, we are still at a very primitive stage in our understanding of the world. One of the things I find interesting is the meaning of observation. Observations occur after and during all sorts of processing by the brain, so it seems natural that observing some system involves all sorts of interaction with the information about it, which would affect the status of the information that is immediately available in the brain. There is no way of knowing how much of what we observe actually relates to things outside of our heads. It seems lot of the focus comes back to how the brain works to process information and other philosophical problems about the mind. Our whole observation of the experimental setup in the two slit experiment is taking place within our brains, including all the measurements. I wonder if the problem has something to do with the status of information transferring from one place to another or one observer to another or something to do with the way our brains process information. I think you mentioned something along those lines but dismissed it without giving any details about the views. One of the hopes of science is that it can lead to some better answers and progress on some of these issues, but it also seems to open new doors that further confound us. You presented a choice between the copenhagen interpretation which is difficult to make sense of, the many worlds interpretation which is equally crazy and leading to all sorts of absurdities, and some sort of hidden variable theory. You didn’t go into too much about why the hidden variable idea does not work. Anyway the discussion raised some interesting issues about the goals of scientific theories and what they can hope to tell us about the world, so I think Quantum mechanics leads to some interesting philosophy. I thought you guys did a good job of explaining many of the issues involved in a clear and concise manner. I thought the guest speaker also did very well. The discussion of Nagel also brought up the distinction between science and pseudoscience. I think it is good to have some level of skepticism in most things–including science. But I think a scientific philosophy is the best way at this time to proceed with trying to understand the world.
#2 by Wes Alwan on January 21, 2010 - 7:54 am
Thanks Dan, glad you enjoyed it. I’m actually sympathetic to both of the positions you describe — the hidden variable theory and the cogsci/Kantian position you describe. I know our guest Dylan discussed the former, but I’m not sure where he came out on that — I forget if it’s been discarded based on the evidence. As for the Kantian position (which I hesitate to mention, since Mark accused me of having a blowup doll of Kant in my room), I think it’s plausible to suggest that quantum inconsistencies belong to a “phenomenal” level but go away at the level of some underlying reality. On the other hand, then we’re confronted with the many problems involved with this kind of epistemology!
#3 by Dan B on January 23, 2010 - 8:21 am
I agree. It might bring in doubt in the validity of scientific observations if we did something like that. There are also a few different versions of the many-worlds interpretation, including the branching version you guys talked about. I have heard of other ones that describe the universe like a sheet of paper in a book. Of course most people find the many-worlds pill a difficult one to swallow. When I first heard of it I thought it was probably a waste of time to even consider. However, it does have some strengths. These aren’t all of them but for one it avoids the need for observers to collapse the world into a particular state, which seems odd. That seems to put us too close to the center of the universe again. Many-worlds also seems to address the problem of this world existing and seeming to be perfectly suited for us. I believe in evolution, but in order for evolution to take place–-for the atoms and molecules to form–the universe has to be set up just right. From what I understand, physicists tell us here are many other ways this universe could have been. If one of the constants in physics were even a tiny fraction different, life could not exist in this universe. If the universe could so easily have been different, and there is only one universe, why did it happen to be one that was suited for life? I am sure you have heard of an argument like this from theists. It seems very improbable that we would get so lucky if there were only one shot at it. However, if every possible universe existed, or at least an extremely high number of universes existed, then this universe may not be as improbable. Then there would be lots of universes like this and we would not be so amazing after all. I am not saying I buy it, but there is something to be said for it. It is a good one to put away in your toolbox. It defeats the need for a creator.
#4 by Nullifidian on June 1, 2011 - 4:04 pm
I’m quite late to this discussion, but if I’m going back through and listening to previous podcasts, then so could anybody else.
The notion that the universe has a few tightly constrained constants that, without being at or near their present levels, would have made it impossible for life to exist is a common theistic argument, and there are more ways of combating it than merely by arguing for multiverses (which albeit is a reasonable outcome of inflationary theory).
One of the flaws in the argument is that they only consider the effect of changing one constant at a time. Victor Stenger, a retired physicist, has argued that we should see what would happen if *all* the fundamental constants were equally likely to vary (because that’s how it would play out in any “birth” of the universe scenario), and he has shown through computer modeling that this considerably improves the likelihood of having a “life-friendly” universe.
http://www.colorado.edu/philosophy/vstenger/Cosmo/MonkeyGod.pdf
Also, there is a probabilistic argument that can be used against the “anthropic principle”—namely, that the people who propose it get their probabilities backwards. Michael Ikeda and Bill Jeffreys have written an article for a proposed FAQ on the “anthropic principle” using the analogy of a poker hand. You are unlikely to win a hand of poker because you are dealt a royal flush; most hands of poker are won with less. But it would be absurd to say that, having been dealt a royal flush, you would be almost certain to *not* win the hand. Likewise, if it is unlikely that a naturalistic universe would be life-friendly, it does not follow from this fact alone that, having a life-friendly universe, it is unlikely to be a naturalistic one. In fact, the overwhelming probability as far as we can determine is that the universe would be naturalistic. If life required a constant adjustment out of nowhere so that it could continue to exist, if everything were dead set against life existing and it did anyway, then we would be entitled to infer that the existence of life was a miracle. But if life needs no support beyond that already provided by the universe, then where is the warrant for inferring a God? It looks very much like having one’s cake and eating it too.
#5 by Nullifidian on June 1, 2011 - 4:05 pm
Whoops.
I meant to link to that Anthropic Principle FAQ too:
http://quasar.as.utexas.edu/anthropic.html
#6 by Dan B on January 23, 2010 - 9:20 am
My observations lead me to believe that my observations are not reliable.
This sentence is false.
#7 by Nullifidian on June 1, 2011 - 4:12 pm
Also, one other recommendation. Victor Stenger, whom I mentioned above, has often dealt with philosophical issues in his books. Three of his best are The Unconscious Quantum: Metaphysics in Modern Physics, where he details the interpretative contexts one can bring to QM of which the Copenhagen Interpretation is just one of many; Timeless Reality, where he argues that much of quantum weirdness becomes straightforward by simply rejecting the notion of an arrow of time operating at the quantum level; and The Comprehensible Cosmos.